A fluid controlling valve device incorporated in a secondary air supplying system which introduces, upon starting up of an engine, secondary air generated in a secondary air flow path pipe into a three way catalytic converter to promote warming up of the three way catalyst is known and disclosed in Japanese Patent Laid-Open No. 2007-24242.
The fluid controlling valve device includes an electric motor, a speed reducing mechanism for reducing the speed of rotation of the electric motor, and a valve shaft or valve rod having a plurality of rack teeth for meshing with a final gear wheel in the speed reducing mechanism and configured to convert the rotational motion of the final gear wheel into linear motion and be displaced integrally with a valve body. In this instance, the electric motor is rotated forwardly or reversely to place the final gear wheel and the rack teeth into meshing engagement with each other to displace the valve body integrally with the valve shaft having the rack teeth to open and close the fluid path.
Meanwhile, a valve device is proposed in Japanese Patent Application No. 2009-229065. In the valve device, a rockable lock lever is provided on a case of the valve device and an engaging portion is formed on a rear face of the rack member, on which the rack teeth are provided, on the opposite side to the rack teeth such that the lock lever is engaged with the engaging portion to retain the valve body, which moves together with the rack member without energization of a rotational driving source, at an open position, that is, at a valve opening position.